There are tonnes of little
key fob cameras, and then a
clip on camera or two available out there.
http://www.chucklohr.com/808/index.shtmlIt is a bit of grab bag, but I have one, and it seems to take decent video.
What I find missing is the image stabilization that higher end cameras feature.
If you look around on Amazon there is a glut of GoPro knock offs, That might sell
for as little as ₤28.
The SJcam 4000 is one of those. Not that it would fit inside
the wheelhouse, but I suppose that depends on how big your tug is scaled.
Of course you would need to purchase a 32gig micro memory card also.